JP2009188128A - Laser irradiation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser irradiation apparatus that allows operator to observe and position the radiation point of laser beam on an object, with an access panel being opened. <P>SOLUTION: When an open/close detecting sensor 21 attached to a laser irradiation apparatus 20 whose safety class exceeds 1 detects opening of a door 14, a control part 22 raises an ND filter 23 of a selected absorption index which is positioned at a waiting point based on an inputted opening detecting signal so that it is inserted into the optical path 4 of the laser beam. Since the ND filter 23 absorbs laser beam and decreases the amount of transmitted light, to attain a safety class of 1, an operator can manually move a test piece 1, while observing an irradiated point P of the laser beam on the test piece 1, for accurate alignment on a predetermined position. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an improvement in safety of a laser irradiation apparatus.

  Laser irradiation apparatuses are used in laser processing machines, analysis / measurement equipment using lasers, medical equipment, and the like. However, since the laser beam has a high energy density, when the laser beam enters the eye of the operator of the laser irradiation apparatus, not only the visual acuity is deteriorated but also there is a risk of blindness in some cases. For this reason, the “Industrial Standard for Laser Products” has been established in the Japanese Industrial Standards. 1 (essentially) for laser products that emit laser beams with different oscillation methods, wavelengths, and outputs based on the effects on the human body. 1M (essentially safe without focusing), 2 (safety), 2M (safe without focusing), 3R (slightly dangerous), 3B (very dangerous), 4 (very dangerous) There is a safety class.

A laser irradiation device with a safety class exceeding 1 must have a protective housing for preventing human exposure to laser radiation (including stray laser radiation). In order to prevent the human body from being exposed to laser radiation when moving or removing an access panel, the access panel must be provided with a safety interlock. In addition, it is said that the laser irradiation device of safety class 3B or 4 must incorporate a control unit by operating a removable key (including a porcelain card), and when the key is removed (interlock) It is said that there should be no exposure by laser radiation (see Non-Patent Document 1).
Japanese Industrial Standard, JIS C6802 (revised in 2005)

  FIG. 4 is a partial cutaway view conceptually showing the above-described laser irradiation apparatus, protective housing, and access panel with a laser irradiation apparatus 10 having a conventional safety class of 3R, for example. That is, the sample 1 which is an object to be irradiated is placed on the sample stage 2, and the laser beam radiated from the laser oscillator 3 in the horizontal direction and traveling in the optical path 4 changes the beam direction directly below by the reflection mirror 6. The sample 1 is irradiated through the condenser lens 8. They are housed in a sample irradiation chamber 12 surrounded by a protective housing 11, and the side wall of the protective housing 11 is accessed so that, for example, the sample stage 2 can be moved manually. A single door 14 that is a panel is provided. When the door 14 is opened by a control unit (not shown), the safety interface for blocking the laser beam optical path 4 with a shutter (not shown) so that the laser is not emitted from the opening of the door 14. A lock is provided.

  In the laser irradiation apparatus 10 shown in FIG. 4, when the door 14 is opened, the laser beam is blocked by the shutter and is not irradiated to the sample 1, so the operator opens the door 14 and sets the irradiation point P of the laser beam on the sample 1. There is a problem that it is not possible to move the sample 1 or the sample stage 2 manually while observing to accurately align the irradiation point P with a predetermined position. Furthermore, in a laser irradiation device of safety class 3B or 4 where a control unit requiring a key operation is provided, when the key is operated for some reason, the door 14 is determined to be closed. The shutter is opened, and a laser beam is emitted to cause the operator to be exposed.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its purpose is to ensure that a human body is exposed to a laser beam by a simple mechanism when the access panel is moved or removed in a laser irradiation apparatus having a safety class exceeding 1. It is an object of the present invention to provide a laser irradiation apparatus that can be prevented from being accidentally detected and can be accurately and safely positioned manually by an operator while observing an irradiation point of a laser beam on an irradiated object.

  In order to achieve the above object, the laser irradiation apparatus of the present invention is linked to the open / close detection sensor of the access panel of the protective housing, and the dimming means that is linked only to the open / close detection sensor and is not operated otherwise. When the operation to open the access panel is started and the open / close detection sensor detects the opening, a dimming means is inserted into the optical path of the laser beam to reduce the amount of transmitted light of the laser beam and Is set to 1.

  As the light reducing means, an ND filter (light reducing filter) that is inserted into the optical path of the laser beam and absorbs the laser beam to reduce the amount of transmitted light is preferably used. A reflection type ND filter that transmits a part of the laser beam but reflects most of the laser beam may be used as a beam splitter. The ND filter and the reflective ND filter may be provided in a bypass optical path that is set so that the laser beam is switched from the original optical path when the open / close detection sensor detects the opening of the access panel.

  According to the present invention, even when a laser irradiation apparatus with a safety class exceeding 1 is in operation, an operation to open the access panel of the protective housing is started, and when the open / close detection sensor detects the opening, Since the light attenuation means is inserted into the optical path to reduce the amount of transmitted light and the safety class is set to 1, the operator manually observes the irradiation point of the attenuated laser beam irradiated to the irradiated object in the protective housing. The irradiated object can be moved by the operation, and the irradiation point can be accurately and safely aligned with a predetermined position.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a partially cutaway view schematically showing components of a laser irradiation apparatus 20 according to the present embodiment. In FIG. 1, the same reference numerals are given to the same components as those of the laser irradiation apparatus 10 of FIG. In the laser irradiation apparatus 20 of the present embodiment, the opening / closing detection sensor 21 of the door 14 is attached to the protective housing 11, and when the opening operation of the door 14 is started, the opening / closing detection sensor 21 that detects the opening opens the control unit. An open detection signal is input to 22. Based on the open detection signal, the control unit 22 moves the ND filter 23 at the standby position indicated by the alternate long and short dash line to the position indicated by the solid line and inserts it into the optical path 4 of the laser beam, absorbs the laser beam and transmits the laser beam. The light quantity is decreased and the safety class of the laser irradiation device 20 is set to 1.

  As the ND filter 23, an absorption type ND filter that absorbs a laser beam by uniformly mixing a light-absorbing substance in a glass substrate is preferably used. Depending on the original safety class of the laser irradiation device 20, the ND filter 23 has different laser beam absorptance, that is, the transmitted light amount is, for example, (1/2), (1/4), (1/8) ),..., (1/400) or (1/1000) is selected as appropriate.

  Next, the operation of the laser irradiation apparatus 20 of the above embodiment will be described. Referring to FIG. 1, in a laser irradiation device 20 having a safety class of 3R, for example, the door 14 is closed, and the absorption type ND filter 23 is in the standby position, and is emitted from the laser oscillator 3 to be the optical path 4. It is assumed that the laser traveling along the direction is also changed in the downward direction by the reflecting mirror 6 and is irradiated on the sample 1 through the condenser lens 8. If the position of the irradiation point P on the sample 1 is not appropriate, it is necessary to accurately position the position of the irradiation point P. In this case, the door 14 is opened by a control unit (not shown), but when opening of the door 14 is started, the open / close detection sensor 21 detects the opening and inputs a detection signal to the control unit 22, based on the input signal. Then, the control unit 22 raises the ND filter 23 at the standby position to the position indicated by the solid line and inserts it into the optical path 4.

The used ND filter 23 sets the safety class of the laser irradiation device 20 to 1, for example, by absorbing most of the laser beam emitted from the laser oscillator 3 of the laser irradiation device 20 whose safety class is 3R. The laser beam transmitted through the ND filter 23 and attenuated continues to irradiate the sample 1. Therefore, if the laser is a visible laser, the operator of the laser irradiation apparatus 20 can observe the laser beam and the irradiation point P with the naked eye. If the laser is an ultraviolet laser, it passes through a fluorescent glass plate (for example, a glass plate containing an ion phosphor such as europium (Eu ³⁺ ) or terbium (Tb ³⁺ )) that absorbs ultraviolet rays and generates fluorescence. If there is a fluorescent glass plate that absorbs infrared rays and generates fluorescence (for example, a glass plate containing a fluoride such as erbium (Er) or ytterbium (Yb)), the invisible laser can be visualized and observed. When the irradiation point P on the surface of the sample 1 is out of the normal position, the irradiation point P can be accurately and safely positioned at a predetermined position by manually moving the sample 1 or the sample stage 2. it can.

  When the door 14 is closed after the position adjustment, the open / close detection sensor 21 detects that the door 14 has been closed and inputs a closing signal to the control unit 22, so the control unit 22 waits for the ND filter 23 from the optical path 4. By returning to the position, the laser beam irradiation returns to the original state.

  In FIG. 1, the ND filter 23 at the standby position is linearly moved based on the opening detection signal of the door 14 input from the open / close detection sensor 21 to the control unit 22 and inserted into the optical path 4 of the laser beam. As shown, a through hole portion and an ND filter portion are provided around the center of the rotary plate arranged perpendicular to the optical path 4 of the laser beam, and the rotary plate is rotated by an open / close detection signal from the open / close detection sensor 21. Thus, the through hole portion and the ND filter portion may be switched. In addition, as shown in FIG. 2 which is a plan view, a pair of reflection mirrors 26 a and 26 d is inserted instead of the ND filter 23, so that the laser beam is reflected in the middle of the optical path 4 and the reflection mirror 26 b and the ND filter 23. In addition, the laser beam may be switched to the bypass optical path 4 ′ including the reflection mirror 26 c and the laser beam transmitted through the ND filter 23 may be returned from the bypass optical path 4 ′ to the original optical path 4.

  Instead of the ND filter 23, a metal thin film or a dielectric thin film is formed on the surface of the glass substrate, and a reflective ND filter 24 that transmits a part of the laser beam but reflects a large part thereof is inserted into the optical path 4. As shown in FIG. 3 which is a plan view, the safety class of the laser irradiation apparatus 20 can be set to 1 by using it as a beam splitter. When the reflection type ND filter 24 is used, the optical path should be configured so that the reflected laser beam does not travel back along the optical path 4 and return to the laser oscillator 3, and the human body is not exposed to the reflected laser beam. In addition, it is preferable that the reflected laser beam is absorbed by the absorber 27.

  The laser irradiation apparatus according to the present invention is a field of laser processing equipment for irradiating a laser beam to a processing object, forming a micro beam, and irradiating a sample with a laser beam and observing the mixed state of a fluorescent substance in the sample under a microscope. In addition, the field of measurement and analysis equipment that performs Raman spectroscopic analysis of components from the Raman spectrum scattered by atoms and ions in the specimen by irradiating the specimen with a laser beam, medical equipment that treats the affected area by irradiating the affected area with a laser beam It can be used effectively in the field. In addition, the laser irradiation apparatus of the present invention is also effectively used when the tip of the laser beam is coupled to one end of the optical fiber so that the optical axis of the laser beam coincides with the central axis of the optical fiber.

It is a figure which shows roughly the structure of the laser irradiation apparatus which concerns on embodiment of this invention, and is an apparatus by which an absorption type ND filter is inserted in the optical path of a laser when a door is open | released. It is a figure which shows roughly the structure of the laser irradiation apparatus of a modification, and is an apparatus which provided the absorption type ND filter mirror in the bypass optical path which switches the optical path of a laser when a door opens. It is the same figure as FIG. 2 at the time of providing the reflection type ND filter used instead of the absorption type ND filter in FIG. It is a figure which shows schematically the structure of the laser irradiation apparatus of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sample 2 Sample stage 3 Laser oscillator 4 Optical path 6 Reflecting mirror 8 Condensing lens 10 Conventional laser irradiation apparatus 11 Protective housing 12 Sample irradiation chamber 14 Door 20 Laser irradiation apparatus 21 Opening / closing detection sensor 22 Control unit 23 ND filter 24 Reflective type ND filter 26 Reflection mirror 27 Laser absorber

Claims (5)

In a laser irradiation device having a safety class of more than 1 for irradiating an irradiated object with a laser beam emitted from a laser oscillator,
An access panel that is part of a protective enclosure surrounding the laser irradiation device and can be opened by movement or removal;
An open / close detection sensor of the access panel;
A dimming unit that is inserted into the optical path of the laser when the open / close detection sensor detects the opening of the access panel to reduce the amount of transmitted light of the laser beam, and
When the opening / closing detection sensor detects the opening of the access panel, the dimming means is inserted into the optical path and the safety class is set to 1. In the laser irradiation apparatus of Claim 1,
The laser irradiating apparatus characterized in that the dimming means is an ND filter (a dimming filter) or a reflective ND filter for reducing the amount of transmitted light of the laser beam. In the laser irradiation apparatus of Claim 2,
A laser irradiation apparatus, wherein the dimming means is directly inserted into the optical path. In the laser irradiation apparatus of Claim 2,
At least a pair of reflecting mirrors are inserted into the optical path, the laser beam is guided to a bypass optical path where the dimming means is disposed, and the laser beam transmitted through the dimming means is returned from the bypass optical path to the original optical path. Laser irradiation apparatus characterized by being a thing. An irradiation system comprising at least a laser oscillator and a sample irradiated with a laser beam from the laser oscillator, a protective housing that surrounds the irradiation system, and an access panel that is a part of the protective housing and is movable or removable A laser irradiation type analyzer comprising a sample irradiation chamber having a laser irradiation on a sample arranged in the sample irradiation chamber,
When the open / close detection sensor of the access panel and the open / close detection sensor detect the opening of the access panel, the laser irradiation type analyzer is inserted into the optical path of the laser beam to reduce the transmitted light amount of the laser beam. A dimming means is provided with a safety class of the type analyzer as 1.
When the access panel is opened, the dimming means is inserted into the optical path of the laser beam according to the open detection signal, so that the irradiation is performed while observing the dimmed laser beam and the irradiation point on the sample. A laser irradiation type analyzer characterized in that the point can be positioned.

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